Field of the Invention
The present invention relates to a plate heat exchanger.
Description of the Related Art
For a paralleled-channel heat exchanger (evaporator), especially, for a plate heat exchanger and a micro channel heat exchanger, mal-distribution of the refrigerant is a worldwide technical problem. Generally, the refrigerant entered into the heat exchanger is in a two-phase manner, since complicated application conditions and two-phase flows, it is hard to achieve uniform distribution of the refrigerant. In most cases, excess liquid refrigerant will flow into some of the channels while excess gaseous refrigerant will flow into some other of the channels, which may greatly impact integral performance of the evaporator.
The prior art solution for refrigerant distribution is achieved based on a distributor technology. There are common measures liking guide duct, guide ring, embedded distributor, etc. The main concept of the prior art solution is to dispose an inlet of each channel of the heat exchanger to have a small circulation cross section, such as a small hole and small slit, to control mass flow rate of the refrigerant into the channel, so as to uniform overall refrigerant distribution. Since aperture size of the distributor is generally about 0.5-2.0 mm, the technology faces great challenges in design and manufacturing.